Area of this shape?

A normal-level "Area" problem.Most area problems have two or more routes. Solve it one way, then check with the other — that is the safest habit.

Hints

The notched shape fits no formula, so first fill in the missing top-right corner to make one big rectangle.
The big rectangle is 10 cm by 12 cm, so its area is 12 × 10 = 120 cm².
Now the missing rectangle. Its width is the bottom side minus the top side: 12 − 7 = 5 cm.
Its height is the left side minus the right side: 10 − 6 = 4 cm. So the missing piece is 5 × 4 = 20 cm².
Subtract the missing piece from the big rectangle: 120 − 20 = 100 cm²
Now try a completely different route. Clear the working lines and instead cut down the middle into two rectangles.
The left is 7 × 10 = 70 cm², the right is 5 × 6 = 30 cm². Together: 100 cm². Subtracting and splitting give the same answer.

Answer 100cm²